I would suggest a closed loop ac Vfd drive with encoder. They are awesome.
I normally. Buy schiender altivar 71 drives cheap second hand. But most brands have them. Second option is a open loop vector control Vfd. They are pretty good. On Tue, Jul 27, 2021, 10:55 AM Earl Weaver <[email protected]> wrote: > Hi, > I have a lathe spindle with 8 in. chuck that is run with a 5HP Reliance > DC Motor and Reliance DC Drive. > I just cannot get much power out of it at low RPM. Was trying to turn > 8in OD steel, at approx. 200 -250 RPM with .005 in. cut. It didn't work, > it just stalled. > When I run it at low RPM the chuck rotation is movable, not firm. > I can take a hold of the chuck and hold it and move it back and forth as > it rotates. > It also is more noisy at low RPM. > > This lathe is a Linuxcnc retrofit with J Elson's Universal PWM > Controller and DAC Spindle control. > The DC drive has tachometer feedback from the motor. > I have tried numerous times to adjust, tune the drive, without success. > I also tried closed loop control from the spindle encoder within LCNC, > also no success. > > So here come the questions: > Should I keep trying to get this DC Drive working or would it be better > to switch to AC Variable Frequency Drive? > If I would switch to AC VFD would 5HP AC Motor be sufficient size for > existing 1:1 ratio double v belt to drive 8" spindle chuck? > What torque at low RPM can I expect for this 5HP DC motor? am I > expecting to much from it? > Would there be a better drive option for the existing DC motor? > Any recommendations? > > Thanks, > -- > Earl Weaver > Email: [email protected] <mailto:[email protected]> > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
